Amplifiers are commonly used in various electronic devices to provide signal amplification. Different types of amplifiers are available for different uses. For example, a wireless communication device such as a cellular phone may include a transmitter and a receiver for bi-directional communication. The receiver may utilize a low noise amplifier (LNA), the transmitter may utilize a power amplifier (PA), and the receiver and transmitter may utilize variable gain amplifiers (VGAs).
A receiver may include an LNA coupled to an antenna via various front-end circuit blocks. These circuit blocks may perform functions such as filtering, switching between the transmitter and the receiver, impedance matching, etc. These circuit blocks may be implemented with discrete components external to an integrated circuit (IC) containing the LNA. The external, or off chip, components increase the cost and size of the receiver. Each of these circuit blocks may also have insertion loss, which degrades the noise figure (NF) of the receiver and hence degrades the performance of the receiver.